True Copies Down Through Time

Something came to me today. I understand that you don't believe in the inerrancy of the Bible. I don't agree with that, but we've wrestled with our difference on this score before. But here's my question: do you believe that the Bible was errant in its original writing, or became errant down through time as manual copies were made, copy made from copy?

I ask because one of the remarkable things about the Bible is that there appears to be a remarkable accuracy in the copies that were made across time. Not 100%, but in the very high 90's, and from what I understand the differences are trivial in nature (admittedly, a subjective judgment).

Now, if the Bible became errant due to progressive infusion of agenda, then it would seem to me that what we'd see is considerably more difference between successive manuscript copies.

Note: and I'm not speaking of translations here, but letter-for-letter copies made in the same language.

Now I can see how one might argue that the original manuscripts might be agenda-laced and therefore errant, and that errancy carried down through true copies. That would align with the apparent evidence of accuracy of copies.

But revisionism tends to develop over time, and that would suggest to me that we should see more migration from the original with each subsequent copy. But we don't.

Thoughts?